scholarly journals Revised Description of the Early Permian Recumbirostran “Microsaur” Nannaroter mckinziei Based on New Fossil Material and Computed Tomographic Data

2021 ◽  
Vol 9 ◽  
Author(s):  
Mark J. MacDougall ◽  
Robert Seeger ◽  
Bryan Gee ◽  
Jasper Ponstein ◽  
Maren Jansen ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Early Permian ◽  
Computed Tomographic ◽  
Lower Jaw ◽  
Fossil Material ◽  
New Information ◽  
Ct Analysis ◽  
Tomographic Data ◽  
Ct Data ◽  
Phylogenetic Character

The early Permian Richards Spur locality of Oklahoma has produced abundant material of numerous terrestrial fossil tetrapods, including various “microsaurs,” several of which are considered to belong to the clade Recumbirostra. We present a new partial skull of the recumbirostran “microsaur” Nannaroter mckinziei; through computed tomography (CT) analysis of both this new specimen and the holotype, we provide an updated description of the taxon. This new description provides novel information regarding several regions that could not be examined previously due to either being absent in the holotype or difficult to access. This includes missing and obscured aspects of the skull roof, braincase, lower jaw, and the palatal region. Furthermore, the new information obtained from this description was used to update phylogenetic character codings of Nannaroter, and a revised phylogenetic analysis was conducted. The results of this updated analysis are congruent with those of other recent phylogenetic analyses of recumbirostran “microsaurs.” This new information adds to the ever-growing body of early tetrapod CT data, which has been, and will continue to be, important in revealing details regarding early tetrapod anatomy, interrelationships, paleoecology, and evolution.

scholarly journals Cranial anatomy of Bolotridon frerensis, an enigmatic cynodont from the Middle Triassic of South Africa, and its phylogenetic significance

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11542
Author(s):  
Luisa C. Pusch ◽  
Christian F. Kammerer ◽  
Jörg Fröbisch
Keyword(s):  
Middle Triassic ◽  
Phylogenetic Analyses ◽  
Data Matrix ◽  
Phylogenetic Position ◽  
Published Data ◽  
Dental Morphology ◽  
Ct Reconstruction ◽  
Computed Tomographic ◽  
Lower Jaw ◽  
Assemblage Zone

The cynodont fauna of the Trirachodon-Kannemeyeria Subzone of the Middle Triassic Cynognathus Assemblage Zone (AZ) is almost exclusively represented by taxa belonging to the clade Eucynodontia. However, there is one basal (non-eucynodont) cynodont known to have survived into this assemblage: the enigmatic Bolotridon frerensis. BSPG 1934-VIII-7 represents by far the most extensive specimen of B. frerensis, consisting of a partial skull with occluded lower jaw. The specimen was initially described by Broili & Schröder (1934), but their description was limited to surface details of the skull and the dental morphology. Here, by using a computed tomographic (CT) reconstruction, we redescribe this specimen, providing novel information on its palatal and internal anatomy. New endocranial characters recognized for this taxon include ridges in the nasal cavity indicating the presence of cartilaginous respiratory turbinals. New data obtained from the CT scan were incorporated into the most recently published data matrix of early non-mammalian cynodonts to test the previously unstable phylogenetic position of Bolotridon. Our phylogenetic analyses recovered Bolotridon as the sister-taxon of Eucynodontia, a more crownward position than previously hypothesized.

scholarly journals New information on the early Permian lanthanosuchoid Feeserpeton oklahomensis based on computed tomography

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7753 ◽  
Author(s):  
Mark J. MacDougall ◽  
Anika Winge ◽  
Jasper Ponstein ◽  
Maren Jansen ◽  
Robert R. Reisz ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Phylogenetic Analyses ◽  
Lower Permian ◽  
Early Permian ◽  
Mandibular Ramus ◽  
Cave Deposits ◽  
New Information ◽  
The Many ◽  
Anatomical Information ◽  
Tomography Data

The cave deposits of the Lower Permian Richards Spur locality in Oklahoma, USA, have produced an incredible number of terrestrial tetrapod taxa, many of which are currently only known from this locality. One of the many recent taxa to be described from the locality was the small lanthanosuchoid parareptile Feeserpeton oklahomensis. Represented by a well-preserved, near complete skull, F. oklahomensis would have been a small predatory reptile, likely preying upon arthropods, and contributes to the extensive tetrapod fauna that was present at Richards Spur. New computed tomography data of the holotype and only specimen has allowed us to visualize and describe previously obscured and inaccessible anatomy of this taxon. These areas include the mandibular ramus, the palate, the sphenethmoid, the epipterygoids, and the braincase. Furthermore, this new anatomical information allowed formerly unknown character codings to be updated, thus we also performed new phylogenetic analyses that incorporated this new information. The results of these updated phylogenetic analyses are very similar to those of past studies, with F. oklahomensis being found as the sister taxon to all other lanthanosuchoids.

scholarly journals A comparison between Asians and Caucasians in the dimensions of the femoral isthmus based on a 3D-CT analysis of 1189 adult femurs

2021 ◽  
Author(s):  
Darius M. Thiesen ◽  
Dimitris Ntalos ◽  
Alexander Korthaus ◽  
Andreas Petersik ◽  
Karl-Heinz Frosch ◽  
...  
Keyword(s):  
Proximal Femur ◽  
Strong Predictor ◽  
Matched Pair ◽  
3D Ct ◽  
Femur Fractures ◽  
Matched Pair Analysis ◽  
Significant Difference ◽  
Ct Analysis ◽  
Ct Data ◽  
The Individual

Abstract Introduction For successful intramedullary implant placement at the femur, such as nailing in unstable proximal femur fractures, the use of an implant that at least reaches or exceeds the femoral isthmus and yields sufficient thickness is recommended. A number of complications after intramedullary femoral nailing have been reported, particularly in Asians. To understand the anatomical features of the proximal femur and their ethnic differences, we aimed to accurately calculate the femoral isthmus dimensions and proximal distance of Asians and Caucasians. Methods In total, 1189 Asian and Caucasian segmented 3D CT data sets of femurs were analyzed. The individual femoral isthmus diameter was precisely computed to investigate whether gender, femur length, age, ethnicity or body mass index have an influence on isthmus diameters. Results The mean isthmus diameter of all femurs was 10.71 ± 2.2 mm. A significantly larger diameter was found in Asians when compared to Caucasians (p < 0.001). Age was a strong predictor of the isthmus diameter variability in females (p < 0.001, adjusted r2 = 0.299). With every year of life, the isthmus showed a widening of 0.08 mm in women. A Matched Pair Analysis of 150 female femurs showed a significant difference between isthmus diameter in Asian and Caucasian femurs (p = 0.05). In 50% of the cases the isthmus was found in a range of 2.4 cm between 16.9 and 19.3 cm distal to the tip of the greater trochanter. The female Asian femur differs from Caucasians as it is wider at the isthmus. Conclusions In absolute values, the proximal isthmus distance did not show much variation but is more proximal in Asians. The detailed data presented may be helpful in the development of future implant designs. The length and thickness of future standard implants may be considered based on the findings.

scholarly journals A Micro-Computed Tomography Comparison of the Porosity in Additively Fabricated CuCr1 Alloy Parts Using Virgin and Surface-Modified Powders

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1995
Author(s):  
Mirko Sinico ◽  
Suraj Dinkar Jadhav ◽  
Ann Witvrouw ◽  
Kim Vanmeensel ◽  
Wim Dewulf
Keyword(s):  
High Energy ◽  
High Energy Density ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Powder Bed ◽  
Metallurgical Defects ◽  
Ct Analysis ◽  
Ct Data ◽  
Surface Modified ◽  
Fusion Pores

Recently, the use of novel CuCr1 surface-modified powder for reliable laser powder-bed fusion (LPBF) manufacturing has been proposed, enabling a broader LPBF processing window and longer powder storage life. Nevertheless, virgin CuCr1 powder is also LPBF processable, on the condition that a high-energy density is employed. In this work, we compare two dense specimens produced from virgin and surface-modified CuCr1 powder. Furthermore, a third sample fabricated from surface-modified powder is characterized to understand an abnormal porosity content initially detected through Archimedes testing. Utilizing high-resolution micro-CT scans, the nature of the defects present in the different samples is revealed. Pores are analyzed in terms of size, morphology and spatial distribution. The micro-CT data reveal that the virgin CuCr1 dense specimen displays keyhole pores plus pit cavities spanning multiple layer thicknesses. On the other hand, the sample fabricated with the surface-modified CuCr1 powder mainly contains small and spherical equi-distributed metallurgical defects. Finally, the CT analysis of the third specimen reveals the presence of a W contamination, favoring lack-of-fusion pores between subsequent LPBF layers. The LPBF melting mode (keyhole or conductive), the properties of the material, and the potential presence of contaminants are connected to the different porosity types and discussed.

Computed Tomography in the Elderly: 1. the Normal Population

1980 ◽  
Vol 136 (3) ◽  
pp. 249-255 ◽  
Author(s):  
Robin J. Jacoby ◽  
Raymond Levy ◽  
John M. Dawson
Keyword(s):  
Psychiatric Patients ◽  
Normal Population ◽  
The Elderly ◽  
Reciprocal Relationship ◽  
Cortical Atrophy ◽  
Global Rating ◽  
Computed Tomographic ◽  
Methodological Problems ◽  
Ct Data ◽  
Healthy Community

SummaryComputed tomographic (CT) and brief psychometric findings on 50 psychiatrically and neurologically healthy community residents over 60 years old are presented. The need for normative CT data is emphasized, and the methodological problems in obtaining them are discussed. Measures of ventricular size were generally found to be greater than those reported by other workers, and variation with age was also found to be less marked than hitherto reported. A reciprocal relationship was found between a global rating of cortical atrophy and a test of memory and orientation. This communication forms the basis for comparison with groups of psychiatric patients to be presented in subsequent articles.

Considerations for Post-processing Parameters in Mixed-Method 3D Analyses

2021 ◽  
Vol 9 (4) ◽  
pp. 325-337
Author(s):  
Robert Z. Selden ◽  
Lauren N. Butaric ◽  
Kersten Bergstrom ◽  
Dennis Van Gerven
Keyword(s):  
Three Dimensional ◽  
Processing Parameters ◽  
Surface Model ◽  
Digital Repositories ◽  
Computed Tomographic ◽  
Archaeological Data ◽  
3D Data ◽  
Morphometric Analyses ◽  
Smoothing Parameters ◽  
Ct Data

ABSTRACTThe production of three-dimensional (3D) digital meshes of surface and computed tomographic (CT) data has become widespread in morphometric analyses of anthropological and archaeological data. Given that processing methods are not standardized, this leaves questions regarding the comparability of processed and digitally curated 3D datasets. The goal of this study was to identify those processing parameters that result in the most consistent fit between CT-derived meshes and a 3D surface model of the same human mandible. Eight meshes, each using unique thresholding and smoothing parameters, were compared to assess whole-object deviations, deviations along curves, and deviations between specific anatomical features on the surface model when compared with the CT scans using a suite of comparison points. Based on calculated gap distances, the mesh that thresholded at “0” with an applied smoothing technique was found to deviate least from the surface model, although it is not the most biologically accurate. Results have implications for aggregated studies that employ multimodal 3D datasets, and caution is recommended for studies that enlist 3D data from websites and digital repositories, particularly if processing parameters are unknown or derived for studies with different research foci.

An Ancient Retrovirus-like Element Contains Hot Spots for SINE Insertion

Genetics ◽  
2001 ◽  
Vol 158 (2) ◽  
pp. 769-777
Author(s):  
Michael A Cantrell ◽  
Brian J Filanoski ◽  
Angela R Ingermann ◽  
Katherine Olsson ◽  
Nicole DiLuglio ◽  
...  
Keyword(s):  
Hot Spots ◽  
Hot Spot ◽  
Phylogenetic Analyses ◽  
Common Ancestry ◽  
Specific Element ◽  
Sine Insertion ◽  
Specific Locus ◽  
Multiple Species ◽  
Phylogenetic Character ◽  
Over Time

Abstract Vertebrate retrotransposons have been used extensively for phylogenetic analyses and studies of molecular evolution. Information can be obtained from specific inserts either by comparing sequence differences that have accumulated over time in orthologous copies of that insert or by determining the presence or absence of that specific element at a particular site. The presence of specific copies has been deemed to be an essentially homoplasy-free phylogenetic character because the probability of multiple independent insertions into any one site has been believed to be nil. Mys elements are a type of LTR-containing retrotransposon present in Sigmodontine rodents. In this study we have shown that one particular insert, mys-9, is an extremely old insert present in multiple species of the genus Peromyscus. We have found that different copies of this insert show a surprising range of sizes, due primarily to a continuing series of SINE (short interspersed element) insertions into this locus. We have identified two hot spots for SINE insertion within mys-9 and at each hot spot have found that two independent SINE insertions have occurred at identical sites. These results have major repercussions for phylogenetic analyses based on SINE insertions, indicating the need for caution when one concludes that the existence of a SINE at a specific locus in multiple individuals is indicative of common ancestry. Although independent insertions at the same locus may be rare, SINE insertions are not homoplasy-free phylogenetic markers.

Computed Tomography in the Elderly 3. Affective Disorder

1980 ◽  
Vol 136 (3) ◽  
pp. 270-275 ◽  
Author(s):  
Robin J. Jacoby ◽  
Raymond Levy
Keyword(s):  
Computed Tomography ◽  
Elderly Patients ◽  
Affective Disorders ◽  
The Elderly ◽  
Consecutive Series ◽  
Healthy Controls ◽  
Ventricular Size ◽  
Radiological Criteria ◽  
Computed Tomographic ◽  
Ct Data

SummaryClinical and computed tomographic (CT) data on a consecutive series of 41 elderly patients with affective disorders are presented, and comparisons made with a group of 50 healthy controls. In both groups ventricular size increased with age, but only in the controls was there an age correlation with sulcal widening. Using clinical and radiological criteria, the prevalence of cerebrovascular disease in the patient group was 12 per cent. A sub-group of patients with enlarged ventricles emerged, whose first depression began later in life, and who at the time of this study were older and showed more ‘endogenous’ features than the remainder. It is suggested that this provides further evidence that organic cerebral factors may have aetiological significance in some depressions of old age.

scholarly journals REGRESSION MODELS OF INDIVIDUAL LINEAR SIZES OF MOLARS DEPENDING ON THE FEATURES OF CEPHALOMETRIC INDICES IN PRACTICALLY HEALTHY MEN OF THE WESTERN AND EASTERN REGIONS OF UKRAINE

2018 ◽  
Vol 24 (1) ◽  
pp. 56-61
Author(s):  
О.О. Kotsyura
Keyword(s):  
Body Length ◽  
Regression Models ◽  
Eastern Region ◽  
Crown Height ◽  
Healthy Men ◽  
Face Type ◽  
Computed Tomographic ◽  
Lower Jaw ◽  
Face Length ◽  
Point Body

Restoration of missing teeth should be done as close as possible to the natural anatomical features of the person's tooth-jaw apparatus. That is why the problem of aesthetics in dentistry has ceased to be only orthopedic and has shifted towards a constitutional and ethnic odontology. The purpose of the study is to construct and carry out analyzes obtained by regression analysis, models of computed-tomographic size of molars, depending on the features of cephalometric indices of practically healthy men of the Western and Eastern regions of Ukraine. A computed-tomographic study of molars with the following odontometry and cephalometry of 36 practically healthy men of the Western region of Ukraine – residents of Volyn, Rivne, Lviv, Chernivtsi, Ternopil, Khmelnytskyi, Transcarpathian and Ivano-Frankivsk regions and 35 men of the Eastern region of Ukraine - residents of Kharkiv, Donetsk and Luhansk regions was performed with the help of the Dental Cone-ray Tomography Veraviewepocs-3D (Morita, Japan). Regression models of linear sizes of molars, depending on cephalometric indices, were conducted using the statistical software package Statistica 6.1. As a result of the conducted research, reliable models of computed-tomographic size of the upper and lower jaws molars were constructed in practically healthy men of the Western [7 models of mesio-distal dimensions (R2 = 0.532-0.646), most of which include sagittal arc (12.5%), outer-eye width, nose depth, distance between nasion and inter-cutter point, body length of the lower jaw on the left, largest head circumference and maximum head length (by 7.5%); 6 models of vestibular-tongue dimensions (R2 = 0.527-0.646), which most often include nasal depth (20.0%), body length of the lower jaw to the left (16.0%), physiological face length and morphological face length (by 12.0%); 1 model of crown height (R2 = 0.579)] as well as Eastern [3 models of crown height (R2 = 0.538-0.682), which most often include nose depth (15.0%), face type, physiological face length, morphological face length, smallest width head and sagittal arc (by 10.0%); 2 models of mesio-distal sizes (R2 = 0.572 and 0.556), which most often include inter eye fossa width (15.4%)] regions of Ukraine. Thus, in practically healthy men from the Western and Eastern administrative-territorial regions of Ukraine, based on the specifics of cephalometric indicators and face type, reliable regression models (with determination coefficient R2 greater than 0.5) of computed-tomographic size of molars of the upper and lower jaws (out of 40 possible 14 for the western and 5 for the eastern regions of Ukraine).

The first potential fossil record of a dibamid reptile (Squamata: Dibamidae): a new taxon from the early Oligocene of Central Mongolia

2019 ◽  
Vol 187 (3) ◽  
pp. 782-799 ◽  
Author(s):  
Andrej Čerňanský
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
New Taxon ◽  
Unique Combination ◽  
Central Mongolia ◽  
Squamate Reptiles ◽  
The Past ◽  
Early Oligocene ◽  
Fossil Material

Abstract Dibamid reptiles have a known current distribution on two continents (Asia and North America). Although this clade represents an early-diverging group in the Squamata and thus should have a long evolutionary history, no fossil record of these peculiar burrowing squamate reptiles has been documented so far. The fossil material described here comes from the early Oligocene of the Valley of Lakes in Central Mongolia. This material consists of jaws and is placed in the clade Dibamidae on the basis of its morphology, which is further confirmed by phylogenetic analyses. In spite of the fragmentary nature of this material, it thus forms the first, but putative, fossil evidence of this clade. If correctly interpreted, this material demonstrates the occurrence of Dibamidae in East Asia in the Palaeogene, indicating its distribution in higher latitudes than today. The preserved elements possess a unique combination of character states, and a new taxon name is therefore erected: Hoeckosaurus mongoliensis sp. nov. The dentary of Hoeckosaurus exhibits some characters of the two extant dibamid taxa. However, the open Meckel’s groove, together with other characters, show that this group was morphologically much more diverse in the past.

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